Mouth sores are holes that form in the lining of the mouth (ulcers) when the top layer of cells breaks down. Mouth sores vary in appearance and size and can affect any part of the mouth, including the lips, tongue, floor of the mouth, and soft palate.

A View of the Mouth

Many mouth sores appear red, but some are white because of dead cells and food debris inside the center portion. Some sores are raised and filled with fluid, similar to blisters.

In people with mouth sores, certain symptoms and characteristics are cause for concern because they may be signs of a systemic disorder. Warning signs include

Fever

Blisters on the skin

Inflammation of the eye

Any sores in people with a weakened immune system (such as people with HIV infection)

Did You Know...

All people with a sore that lasts for 10 days or more must be examined by a dentist or doctor to determine whether the sore is cancerous, precancerous, or not.

People who have warning signs should see a doctor right away. People who have no warning signs but have a lot of pain, feel generally ill, and/or have trouble eating should see a doctor within several days.

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